Cold chisel



Sept. 22, 1925 Y A. R. THOMSON CLD cHIsEL Filed July 5, 1924 lo f m 10, ,Mm 7 Wwf/ w k f 5 r., 1. m

Patented Sept. 22, 1925. n

vUNITED STATES ALBERT R. THOMSON, OF DERBY, CONNECTICUT.

COLD CHISEL.

Application iled July 5,1924. Serial No. 724,468.

To all whom it may concern:

Be it known that I, ALBERT R. THOMSON, a citizen of the United States, residing at Derby, in the county Of New Haven and State of Connecticut, have invented certain new and useful Improvements in Cold Chisels, of which the following is a specification.

My invention relates to improvements in cold chisels, and the Object of my improvement is to produce a cold chisel by the drop forging process that is of such form as to facilitate the details of manufacture; that will permit of relative economy in the material; and that, under conditions of use, will be relatively light and of ample strength so as to be efficient and reliable.

In the accompanying drawing Figure 1 is a side elevation of my improved cold chisel.

Figure 2 is a plan view of the same.

Figure 3 is an end view of the same.

Figure 4 is an end view of the other end.

Figure 5 is a sectional view on the line r 5 5 of Fig. 2.

Figure 6 is a sectional view on the line 6 6 of Fig. 2.

Figure 7 is a longitudinal sectional view on the line 7-7 of Fig. l.

Figure 8 is a plan view of the forged blank with a representation of the fin that is formed in the drop forging process.

My improved cold chisel comprises a handle 10 that terminates at one end in the form of a conical butt 11 and at the other end merges with the blade 12, the latter terminating in thesharpened bit 13.

The blank is formed from bar stock by drop forging and the lin 111 formed by the forging is trimmed off.

The handle l() is formed so as to have an I-beam-shape for the cross-section, comprising relatively deep or thick and flanged border edge portions 15 that are connected by the central web-structure 16.

The blade 12 is relatively elongated and of substantially uniform thickness and such thickness is substantially equal to the thickness atthe axial portion 17 of the handle, being the portion of least thickness between the opposed faces 18 of the web-structure 16.

The handle 10, except for the portion adjacent the butt 11, is of uniform width.

The blade 12 from the junction 19 with the handle 10 `flares outwardly along the sides or side edges i2() so that the width adjacent the bit 13 is wider than at the said junction 19. Y

Considering the details of a cold chisel that would be designated as of one-inch size, the handle 10 would be about three-quarters of an inch wide; would have a thickness for the border edge portions 15 of three-eighths of an inch; and would have for the minimum thickness of the web-structure 16 along the axis One-eighth of an inch.

The thickness of the blade 12 would be substantially one-eighth of an inch to correspond to that of the web-structure mentioned and the width thereof would vary from three-quarters of an inch at the junction 19 to a full inch at the bit 13.

Thus at the bit 13 the material would have a cross-section of one-eighth of an inch by one inch. In the formation of my improved cold chisel it is this dimension that is used to determine the size of the stock to be used and the details of the handle are constructed and arranged so that the crosssection of the handle will have an area substantially equal to that of the blade at the widest part as described.

The cold chisel described may be briefly described as being relatively flat so as to lie easily on the handle or rest on the handle. This feature is of importance in the manufacture in that it facilitates the removal of the fin 14 by reason of the fact that it will easily find the proper position in the dies for effecting the trimming.

I claim as my invention 1. A cold chisel comprising an edge at one end and a blade extending inwardly therefrom, having a butt at the other end and a handle extending inwardly therefrom and merging with said blade, the structure having a substantially uniform thickness for the middle or axial portion of said blade and handle, and the material on each side of said middle or axial portion being projected outwardly laterally in the case of the blade to form a relatively wide blade and in the case of the handle being built-up to provide relatively thick rib-like side members for said handle. f

2. A cold chisel having a handle and a blade that have substantially equal areas of cross-section and that differ in the distribution of the material that form said crosssections, the material of the blade being projected outwardly laterally to provide a relatively wide blade, and the material of the handle built-up to provide thickness at the sides and anI-heam form for the cross-section.

3. A cold chisel having a handle of I- beam form of cross-section, with rib-like enlargements along the edges and a valley along the middle of each of the opposite faces, a blade merging with said handle, of'

greater Width than said handle, and having a. thickness such that the faces merge with the bottoms of said valleys at the junctions with said handle, and said handle being operatively relatively flat so as to provide stability when used as a base-support in manufacture in the trimming operation and when ling on a bench or the like under conditions o use.

ALBERT R. THOMSON. 

